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BGP Default-Originate insights

BGP has multiple ways of advertising a default route to its neighbors;  the neighbor default-originate command is one of these methods and used to advertise a default route to a specific neighbor. Below are some characteristics of the default route advertised by this way. Originator router: Default route does not …

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Understanding BGP communities

What are BGP communities? The BGP community attribute is a numerical value that can be assigned to a specific prefix and advertised to other neighbors. When the neighbor receives the prefix it will examine the community value and take proper action whether it is filtering or modifying other attributes. By …

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BGP helicopter view

If you ask someone some simple BGP questions, like why do iBGP peers need to be fully meshed, and does this have anything to do with Synchronization, and do we need to run BGP on all the network routers, and so on, you can get him into the confusion area, …

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How-to:Configure BGP aggregation Part2

In the first post we explored the basic configuration of BGP route aggregation with and without the summary-only keyword. In todays post our task is to explore the suppress-map keyword using the same topology used in the first post. “please refer Part1 or the series for R1&R2 configuration and network …

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How-to:Configure BGP aggregation Part1

In this series we will explore how route aggregation is accomplished in BGP, We am going to split this topic into multiple posts in order to keep things simple and manageable. Our Network is shown in the digram below. R1 is directly connected to R2 and BGP is basically configured …

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BGP fast-external-fallover

This command is enabled by default on CISCO IOS. The command terminates external BGP sessions of any directly adjacent peer if the link used to reach the peer goes down; without waiting for the hold-down timer to expire. Although this feature improves the BGP conversion time, it may lead to …

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